package 力扣.二叉树相关问题;
public class 翻转二叉树 {

    public class TreeNode {
      int val;
      TreeNode left;
      TreeNode right;
      TreeNode() {}
      TreeNode(int val) { this.val = val; }
      TreeNode(int val, TreeNode left, TreeNode right) {
          this.val = val;
          this.left = left;
          this.right = right;
      }
  }
    public TreeNode invertTree(TreeNode root) {
         if (root==null){
             return root;
         }
         //将根节点的左右节点调换
        TreeNode m=root.left;
         root.left=root.right;
         root.right=m;

         invertTree(root.left);
         invertTree(root.right);
         return root;
    }
}
